LCC and LSU.for crops improvement and production
- 2. • Grouping of land units into defined classes based on their capability. • Capability - depends on their limitations & it is designed to emphasize on the hazards in different kinds of soils. • It serves as a guide to assess the suitability of different land units for arable crops, grazing / forestry. • Depending on the nutritional and other properties soils behave differently. • Some are suitable for cultivated crops, others for pastures and still others may be suitable only for forestry (or) recreation.
- 3. • Criteria used for assessing a land unit - physical land properties & degree of limitation with which crop growth is inhibited. It is mainly based on 1. Inherent soil properties 2. External land features 3. Environmental factors that limit land use (climate vegetative)
- 4. 1ST two information - standard soil survey report and 3rd information - other agencies (or) sources. The factors determining the capability of a soil Depth of soils stoniness, rockiness Texture and structure of soil Permeability (Movement of air and water through the soil) Relief (as expressed by slope) Extent of erosion Susceptibility to over flow, flooding and degree of wetness. Presence of toxic salts, alkali and other unfavourable chemical properties such as pH, gypsum salts, Al etc. Climatic variation (in respect of soil temperature and moisture regimes)
- 5. The capability classification consists of three categories namely 1. Capability classes 2. Capability sub-classes 3. Capability units Capability classes • 8 capability classes are recognized. • The soils having greatest capability for response to management and least limitations are grouped in class – I and those having least capability and greatest limitations are grouped in class-VIII.
- 6. Land suitable for cultivation Land not suitable for cultivation Land capability class Land capability class Class I Very good land (No limitation) Class II Good land (Minor limitation) Class III Moderately good (major limitation) Class IV Fairly good (major limitation with occasional cultivation) Suitable for pasture and grazing Class VIII suitable for wild life and recreation Class V (No limitation) Class VI (Minor limitation) Class VII (Minor Limitation) Land capability classifications (Eight classes)
- 7. Brief description / salient features of LCC Name of the class Colour shown on land capability Salient features Crop suitability crops Management practices Class – I Green Excellent cultivable deep, nearly level. Productive land with no limitation (or very slight hazard) Suitable for most crops like wheat, barley, cotton, maize tomato and beat Need no management practices for cultivation Class – II Yellow Good cultivable land on almost level plain or on gentle slopes limitation of soil depth, salinity, texture, drainage / erosion that reduces the choice of plants Suitable for wheat, barley, cotton Moderately suitable for maize, alfalfa, tomato Slightly suitable for beans Cultivate with precaution need simple management practices.
- 8. Name of the class Colour shown on land capability Salient features Crop suitability crops Management practices Class III Brown Moderately good cultivable land on almost level plain or on moderate slope. Limitation :L Moderate erosion soil depth, soil salinity and soil texture. They may have vertic characteristics (or) drainage problem that reduces the choice of crops Unsuitable for growing vegetable crops. Varying suitability for different crops Cultivation with careful management practices need intensive care. Class IV Pink Fairly good land on almost level plains or moderately steep slopes Limitations Strong / very strong soil salinity S3/S4 shallow soil depth, strong erosion, fine soil texture. Poor (or) excessive drainage. Limited cultivation unsuitable for growing a variety of crops. Suitable for selected crops 8 for pasture. Not economical to cultivate Need intensive soil conservation and management practices
- 9. Name of the class Colour shown on land capability Salient features Crop suitability crops Management practices Class V Dark grey Limitations Story, rocky nature (or) marshy-ness use of implements is difficult Not suitable for arable farming suitable for grazing Class VI Orange Moderate limitation such as steep slope severe erosion, limiting soil depth, strongly gypsiferous, stony or sandy (sand – done areas) eg. dense forest lands of the Himalays. Sandy (gypsiferous) and donal areas of Thar Desert in Rajasthan and SW Irag. Non-arable land well suited for grazing (or) forestry
- 10. Name of the class Colour shown on land capability Salient features Crop suitability crops Management practices Class VII Red Severe limitation such as steeply sloping land subjected to erosion (or) very shallow stony soils that have not Fairly well suited for grazing or forestry but not cultivable Need careful management for grazing and forestry Class VIII Purple Severe limitation Very steeply sloping, highly eroded, rocky barren mountain landscape, hyper arid rocky undulating surface Non-arable, suitable for wildlife (or) recreation. Extremely rough, rocky, arid, wet (or) extremely saline land
- 11. Capability subclasses • The capability subclasses are based on kinds of dominant such as wetness or excess water (w), Climate (C), soil (S) and erosion (e). • The subclasses are mapped by adding limitation symbols to the capability class number subscripts for example II e, IIIw etc. • The capability subclasses provide information as to the kind of conservation problems or limitations involved. • There are no sub-classes in capability class-I land, since there is no limitation in this class.
- 12. Capability units : A capability unit includes soils which are sufficiently uniform in their characteristics, potential and limitations and require fairly uniform conservation treatment and management practices. It the existing limitations can be permanently removed (or) reduced in extent by proper conservation measures (or) management practices, such as provision of irrigation, drainage, control of gullies and construction of flood – retarding irrigation structures, then the land capability class can be changed towards a better class. A further deterioration in the existing conditions will shift the capability to a worse class.
- 14. • Each plant species require definite soil and site conditions for its optimum growth. • Some plants may be found to grow under different soils and extreme agro-ecological conditions, all the plants cannot grow in the same soil and under the same environment. • Success or failure of a plant species to grow in a particular soil and site - climate, availability of water and plant nutrients. • Water and nutrient availability - controlled by the soil physical, chemical and physico-chemical properties. • Based on the soil properties and climatic data, the suitability of the land to support different crops can be worked out following the FAO guide lines (1976).
- 15. Suitability criteria • Most of the plant species need well drained, moderately fine to medium textured soils, free of salinity and having optimum physical environment. • Soil resource maps - predicting the behavior and suitability of soils for growing field crops and forest or plantation crops, once the suitability criteria is established. • The suitability of a land is classified into different categories consisting of Order, Class, Subclass and Unit. Order • Land Suitability Orders denote the kind of suitability. • There are two land suitability orders namely 'S' and 'N’. • 'S' denotes that the land is suitable for crop cultivation and 'N' denotes unsuitable.
- 16. Class • The classes denote the degree of limitations. • There are 3 classes under the order S (S1, S2 and S3) and 2 classes under the order N (N1 and N2) reflecting the degree of suitability within the order. S1 - Highly suitable with no limitations (Green) S2 - Moderately suitable with moderate limitations (Yellow) S3 - Marginally suitable with severe limitations (Brown) N1 - Currently not suitable (Red) N2 - Permanently not suitable (Violet)
- 17. Sub class The sub-classes reflect the kind of limitations or the improvement measures required within a class. These are indicated by symbols using lower case letters following the arabic numerals used for classes. The following are the sub-classes: 1) Climate (c) (included different weather parameters) 2) Topography and landscape (t) 3) Wetness conditions of soil (w) Drainage Flooding
- 18. 4) Physical conditions of soil (s) Texture Gravel / stoniness (Surface soil, subsurface soils) Depth Lime / Calcium carbonate Gypsum 5) Soil fertility (f) (not easily correctable) Organic matter Cation exchange capacity Base saturation Nutrient availability 6) Salinity and alkalinity (n) Salinity Groundwater quality Alkalinity / Sodicity
- 19. Unit The land suitability unit is similar in management requirements. This suggests the relative importance of land improvement works. It is indicated by Arabic numerals enclosed in paranthesis, following the sub class symbol.